Variable-speed-transmission gearing



SePf- 30, 1930 A l l.. K. .MURRAY 1,777,103

VARIABLE SPEED TRANSMISSION GEARING Filed July 125I 1928 Lgf I Patented Sept. 30,l 1930 l l UNiTEosTA'T-Esf vP'a'frizhrr orifice LEE xYiusToN minnaar, or SYDNEY, Naw scura wALns, avermi;

vAnIABLn-srEEn-,rnansmssrou emma' j Application led July 13, 1988, Serial No l0 drum and the driving 'shaft extends axially through this drum,;and carries it. rIfhe couplin between the driving shaft and the drum is a slipping coupling of the hydraulic circulating pump type. The invention resides in the structural features of this coupling and comprises the provision of two spur gear opposite ends of a closed drum and disposed diametrically opposite to eachother to procure static balance-of the drum, said pumps `operating in unison but independently of each other, their deliveries being controlled by a single valve which is located within the drum but external to the pumps, and which is adjustable manually to vary therate of iiow of oil. When the valveis shut off, passage of oilout of thedelivery chambers of the pump casings is checked, and rotation of the O'ear wheels being thus checked, the system becomes locked, and the drum and driven r shaft are in eiect thus directly coupled to the driving shaft. This is the direct drive position. When the vvalve is opened more or less, oil may pass out of the pump delivery $5 chambers, with the result that the meshed permitted to rotate, slip, represented by fthe rate at which the oil is permitted to circulate, taking place, so,l that the driven shaft 4D is rotated, but at a slower rate than the driving'shaft. When the valve is fully opened, the reaction component is lost and there' is' total slip and the drum is then no longer ro` tated though the'driving shaft is maintained -in rotation.

In the accompanying drawing V v Fig. 1 is a longitudinal sectional elevation of a couplin 'according to the invention, appropriately esigned for installation as trans'- mission equipment for an automobile; and- .2--2 f The primary or drivin shaft 10 is direct 292,344, and in- Ausmua August 1, 1927.

` yFi .2 is a transverse section Iin the plane connected to the engine t rough the driven l element ofthe clutch (not shown), and it 66 carries thev vclosed drum 11 rotatably on it, 12 and 13 being taper roller Abearings in the :drumvheads 14 and 15. A fian e 19 on the forwardend of the driven shal (propeller shaft) 16 is fixed to the back head 15 ofthe 60 drum 11 by studs 17 or otherwi Ie, and 'a bearing, indicated at 18, is provide to'carry that end of the driven shaftand through it to support the overhanging weivht of the drum and Vthe overhangin Twol oil pumps are fitted within the drum,` with their casings respe tively fixed to the two covers of thedrum. Only one pump is essential, but-'it is highl advantageous to 70 fit two pumps'as shown and to control both 4of them simultaneously by one valve.

Each pump casing 20 consists of a vchamber, one side of which is open and flanged. Theopen side is fitted up to a head of the drum and is secured thereto by bolts 21. The casing is very accurately machmed on the interior back face of it and also at opposite ends of itto make sliding contact with the teeth tips and the sides of a pair of intermeshedA spur wheels 22 and 23. The contact at the teethtips extends over a-semi-c1rcul lar arcH for each of the wheels. The spur wheel 22 is keyed on4 the driving'shaft 10 and -the spur wheel 23 is freely rotatable on an 85 gear wheels which function as a pump are axle 24 which is carried by the housing. The sides of the wheels 22 and 23 are neat ts on the flat back wall lof the casing 20 and the y interior face of the drumhead respectively. 25 and 26 are shim lates vwhich are lnset 1n 90 the casing wall and 1n the drum head respectively to obtainaccurate fitting whlch will substantiall prevent leaka e of oil backj ward over t e sides of the w eels 22 and 23. Stuing .boxes 4are'fitted to prevent leakage. 96 `of oil along the shaft 10. I27 is an oilintake port in one wall of the casing, entering the pump intake chamber 49' opposite the intermeshing teethof the' wheels22 and 23, and

28 is the delivery chamber ofthe pump. 100 y weight of the driving mi`4 shaft extension within the drum. oil pumps, the casings of which are-fixed to 29 is a pipe led from the delivery chamber 28 to the control valve casinor 30. 31 is a slotted plug which is adjustabe in the valve casing 30 to control the rate of circulation of oil. A crank arm 32 fixed to the spindle of this plug is connected by a link to a thrust pin 33 which is fixed in the top side of the control rod 34. That rod is movable longitudinally in the drum; it passes into it' through a stuiling box 35 tted in one head of the drum, and its inner end is supported in a slide bearing 36. A spring 37 may be -itted to force the rod 34 in one direction, thus to set the valve at either full closed position or at full open position as may be desirable. In automobile equipment the spring should be arranged to move the valve to the fully closed position. The outer end of the rod 34 is connected to a fork lever 38 by a pin and slot joint 39. The lever fulcrum 40 is carried on a bracket 41which is cast on or fixed to the fore end head of the drum, and its fork ends carry pivot pins 42 on runl ners 43 which are grooved to run over the flange 44 on the sleeve 45, which is slidable endwise on the shell of the stulling box 46 through which the driving shaft 10 passes into the drum. The sleeve is slidable by means of a manually operatable arm .47.

' By tting two pumps,one at either end ofthe drum, with their weights oppositel'y p disposed in relation to the drum axis, static balancing of the di-um is facilitated; counterweights to procure dynamic balancing should also be fitted this is an important point when the coupling is required to be operated at `high speed, as then the effect of centrifugal force 1s considerable. The control of the two pumps though one v alve is also advantageous as it procures equalization of the tor ue.

. e operation of the coupling is as follows Let it be assumed that the sleeve 45 is moved by means of the arm 47 to the fullout position at which the rod 34 is drawn voutward and the valve plug 31 is rotated to the full open position. .The drum is charged .with oilto about centre level. The shaft 10 being now rotated, the spur wheel 22 turnin with it, the spur wheel 23 which is in mes with ,the wheel 22 also rotates.` The direction of rotation is shown by arrows. Oil passes into the casin 20 through the port 27, and filling the tooi spaces of the spur wheels as they sweep through the intake is offered to this circulation of oil, the torque applied to the drum is also small and is not sufficient to rotate it against a load. When the control 47 is moved to partially close the valve 31, the oil circulation is throttled more or less, and resistance is imposed against the rotation of the spur wheels? This resistance produces a reactlon component which operates to rotate the drum 11 at a rate lower than the rate of rotation of the shaft 10, the difference between the respective rates of rotation of the drum and the shaft corresponding with the degree of opening of the valve 31 and the consequent rate of oil circulation. When the control is moved to fully close the valve 31, the oil circulation is arrested, and the drum is then in effect locked to the shaft 10 by the oil under compression in the delivery chamber 28, and the shaft 16 then turns at the same speed as the shaft '10. The coupling is therefore immediately variable to rocure any drive-driven ratio between n1l and unity by adjustment of the valve. Accidental back leakage of oil between the spur gears and the gear casing will be practically negligible' when the itting is satisfactorily neat, and whatever leak does occur will pass back to the charge in the drum and'will not be' lost. The drum radl-` including a driven shaft, a closed drum constituting an oil reservoir fixed to said shaft bearings in the ends of said drum, a co-axial driving shaft extending into said drum and working in said bearings, two separate caslngs `fixed to said drum, two independently operating spur gear oil pumps mounted respectively within said casings, a control valve, a port directly connecting the inlet chamber of each pump -with the oil reservoir, means for directly connecting the delivery chamber of each pump with said control valve, andv means for operating said valve to control the flow of oil.

2. A variable speed transmission gearing according to claim 1, in which the oil pump casings are fixed respectively to opposite ends of the oil reservoir and disposed diametrically opposite to each other to procure static balance.

3. A variable speed transmission gearing according to claim 1, stuing boxes tted on the driving shaft to prevent leakage ofoil.

4. In a variable speed transmisslon gearing accordin ,to claim 1, pipeconnectlons from the de ivery chamber of each pump to the control valve, a stuing box on one side of the drum, -a sliding rod extending through said stuffing box, an operatin connection between said rod and said va. ve, a

' 10 sleeve slidably mounted on the driving shaft,

means for shding said sleeve, and connecting means between said rod and said sleeve for o eratin said valve.

v5. n a varlable speed transmission gearin according. to claim 1, a sliding rod extending through one end of the drum, an operatin connection between said rod and the' contro valve, a spring for maintaining said rod and said valve in a. predetermined position, and means for sliding said rod to operate' said valve. e v

6. In a variable speed transmission gearing according to claim 1, a sliding rod extending through one end of the drum, an operating connection between said rod and the control 'valve,'a' spring for maintaining said rod, and said valve in a predetermined osition, a sliding sleeve co-axially mounte in relation to the drum means for sliding said sleeve endwise, a colar on said sleeve, grooved runners ada ted to run on said collar, a bracket fixed to` t e drum, and a forked lever fulcrumed e on said bracket, said lever being articulated at its forked end to said runners andvat its.

l other end .to said rod to apply endwise movement to the rod toA operate 4the control'va'lve. y In testimolg' whereof I aix my si ature.

LE KYNASTON MUR Y. 

